Question 2 (30 marks) An industrial monitoring system uses an loT network comprising many different sensors, IoT devices, detectors and cameras to measure and check a range of parameters from temperature,

pressure and fluid levels to fire and gas detection within a remote working environment. The following calculations relate to Section 4.2 Data for the Internet of Things'. i. a. il. The monitoring system includes an accurate temperature sensor which provides a 10-bit °C reading which comprises an 8-bit integer with 2 extra bits (to the right of the binary point) giving additional numerical precision for each measurement (Section 4.2.2). If the current sensor reading value is 01110111.11, what is the equivalent °C denary value? (2 marks) The current loT sensor monitoring fluid levels has five possible output values (Empty, Low, Medium, High, Full). If fixed-length coding (Sections 4.2.3 and 4.2.4) is used, how many bits are required to represent this loT sensor's output? Comment on whether fixed-length coding is the most efficient way of representing this loT sensor's readings. If not, and by providing a reason, explain what alternative method you would recommend is used. (4 marks) iii. It emerges that the current five output levels of the loT sensor in part (ii) provide inadequate resolution for the fluid level measuring application. The sensor is therefore to be replaced by a new sensor which has 32 output levels. If fixed- length coding is again used, how many bits are required for the new sensor's outputs? If all the output levels for the new loT sensor have the same likelihood of occurring, state whether using fixed-length coding is the best option for this application, giving a reason for your answer. (3 marks) iv. For surveillance purposes, a video camera is used as part of the monitoring environment, which has a frame resolution of 1920 by 1080 pixels. If the colour information in each frame is 24 bits per pixel and the number of frames per second is 15, what will be the total amount of data stored, in MB (Section 1.5 and Activity 3.20) for 1 second of video? Give your answer in scientific notation to two decimal places. Hint: firstly, calculate the total number of pixels in a single video frame. (5 marks) (14 marks)/nb. (14 marks) I. A mobile base station (BS) in an urban environment has a power measurement of 45 µW at 285 m. If the propagation follows an inverse 4th power law (Section 3.2.2), what is a reasonable power value, in µW, to assume 1.14 km from the BS? Express your answer in scientific notation to 2 decimal places. (5 marks) ii. While you are travelling, the mobile phone app you have installed displays a received signal strength of 72 nW. Assuming the same propagation law as in part (i), how far are you from the BS? Give your answer in km to two decimal places. Copyright © 2023 The Open University Question 2 (30 marks) Hint: see Activity 3.6 and Tables 3.1 and 3.5. (3 marks) 4 of 13 08/09/23/nC. 1. The 7-bit ASCII code for the character 'X' is: 1011000 An even parity check bit is included at the start of this code (left-hand end), so that 8 bits are transmitted. What will be the transmitted code for the ASCII character 'X'? (2 marks) il. If this 8-bit ASCII character is transmitted using frequency shift keying modulation (Section 3.3.3), sketch the transmitted waveform. (3 marks) iii. If even parity check bits are used, which of the following 8-bit received ASCII codes are invalid? In each case, give a reason for your choice. • 10110101 • 11110110 • 10100100 (3 marks) (8 marks)